Bug 2519583

Summary:	CVE-2026-70453 rsync: rsync: Denial of Service via Algorithmic Complexity [fedora-all]
Product:	[Fedora] Fedora	Reporter:	Srikanth Balasubramanian <sbalasub>
Component:	rsync	Assignee:	Michal Ruprich <mruprich>
Status:	CLOSED ERRATA	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	rawhide	CC:	luhliari, mruprich, ssorce
Target Milestone:	---	Keywords:	Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	{"flaws": ["7adcc6d2-4a2b-4e0b-9a58-03cdd02560c9"]}
Fixed In Version:	rsync-3.5.0-1.fc44 rsync-3.5.0-1.fc43	Doc Type:	---
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2026-08-22 01:24:35 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	2515403

Description Srikanth Balasubramanian 2026-08-19 14:14:26 UTC

Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

rsync before 3.5.0 contains an algorithmic complexity vulnerability in the hash_search() function that allows a remote attacker to cause a denial of service by delivering a carefully constructed file list. A sender can exploit the quadratic-time worst-case behavior in hash lookups to exhaust receiver CPU resources with a modest number of crafted entries, causing a sustained denial of service.

Comment 1 Fedora Update System 2026-08-20 12:50:03 UTC

FEDORA-2026-bfae8723e2 (rsync-3.5.0-1.fc44) has been submitted as an update to Fedora 44.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-bfae8723e2

Comment 2 Fedora Update System 2026-08-20 12:50:32 UTC

FEDORA-2026-d6763b4c84 (rsync-3.5.0-1.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-d6763b4c84

Comment 3 Fedora Update System 2026-08-21 05:41:30 UTC

FEDORA-2026-bfae8723e2 has been pushed to the Fedora 44 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-bfae8723e2`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-bfae8723e2

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 4 Fedora Update System 2026-08-21 06:00:37 UTC

FEDORA-2026-d6763b4c84 has been pushed to the Fedora 43 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-d6763b4c84`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-d6763b4c84

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 5 Fedora Update System 2026-08-22 01:24:35 UTC

FEDORA-2026-bfae8723e2 (rsync-3.5.0-1.fc44) has been pushed to the Fedora 44 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 6 Fedora Update System 2026-08-27 01:11:24 UTC

FEDORA-2026-d6763b4c84 (rsync-3.5.0-1.fc43) has been pushed to the Fedora 43 stable repository.
If problem still persists, please make note of it in this bug report.